Answer:
Given the following list of densities, which materials would float in a molten vat of lead provided that they do not themselves melt?
Densities (g/mL): lead = 11.4, glass = 2.6, gold = 19.3, charcoal = 0.57, platinum = 21.4.
glass and charcoal
Explanation:
The density of molten lead is about 10.65Kg/m^3
By Archimedes principles, the buoyancy of an object in a fluid is proportional to the mass of fluid displaced
which in turn is proportional to the object's density
Generally an object well float when placed on a denser medium
glass =2.6, and charcoal =0.57 are both less dense so they will float on Lead
Answer:
- <em>As the temperature of a sample of matter is increased, the average kinetic energy of the particles in the sample </em><u>increase</u><em>.</em>
Explanation:
The <em>temperature</em> of a substance is the measure of the <em>average kinetic energy </em>of its partilces.
The temperature, i.e. how hot or cold is a substance, is the result of the collisions of the particles (atoms or molecules) of matter.
The kinetic theory of gases states that, if the temperature is the same, the average kinetic energy of any gas is the same, regardless the gas and other conditions.
This equation expresses it:
Where Avg KE is the average kinetic energy, R is the universal constant of gases, N is Avogadro's constnat, and T is the temperature measure in absolute scale (Kelvin).
As you see, in that equation Avg KE is propotional to T, which means that as the temperature is increased, the average kinetic energy increases.
Answer:
In the same phase
Explanation:
Because when you make a solution you have to keep them in the same phase or you will oof.
I would think the last one about the ozone layer
Answer:
We'll have 1 mol Al2O3 and 3 moles H2
Explanation:
Step 1: data given
Numer of moles of aluminium = 2 moles
Number of moles of H2O = 6 moles
Step 2: The balanced equation
2Al + 3H2O → Al2O3 + 3H2
Step 3: Calculate the limiting reactant
For 2 moles Al we need 3 moles H2O to produce 1 mol Al2O3 and 3 moles H2
Aluminium is the limiting reactant. It will completely be consumed (2 moles).
H2O is in excess. There will react 3/2 * 2 = 3 moles
There will remain 6 - 3 = 3 moles
Step 4: Calculate moles products
For 2 moles Al we need 3 moles H2O to produce 1 mol Al2O3 and 3 moles H2
For 2 moles Al we'll have 2/1 = 1 mol Al2O3
For 2 moles Al We'll have 3/2 * 2 = 3 moles H2
We'll have 1 mol Al2O3 and 3 moles H2
